Reason for getting verticle line on acer laptop screen

[jenny jane]

yesterday i started my laptop(i have acer i5 travelmate 4740) n noticed the yellow verticle line on my screen...i restarted my laptop but it was there,after working on it for many hours line was still there.can any body tell me the reason of appearing this line,does it happened because of hardware issue or some thing happened by me like (some pressure on screen n it get damaged?

 

[ex_bubblehead]

Failing display panel or loose/broken ribbon cable between display and motherboard are the 2 most likely causes.